straphanger vs commuter

straphanger and commuter both are nouns.

Word	Noun	Adjective	Verb	Adverb
straphanger	Yes	No	No	No
commuter	Yes	No	No	No

As nouns, commuter is a hypernym of straphanger; that is, commuter is a word with a broader meaning than straphanger:

straphanger: a commuter who uses public transportation
commuter: someone who travels regularly from home in a suburb to work in a city

straphanger (noun)	commuter (noun)
a standing subway or bus passenger who grips a hanging strap for support	a passenger train that is ridden primarily by passengers who travel regularly from one place to another
a commuter who uses public transportation	someone who travels regularly from home in a suburb to work in a city